Chef is burning calories the hard way

It sees runners tackle obstacles from freezing ice pits to barbed wire and, of course, leaping through flames.

Markus is competing in all seven spartan races in 2013.

"I ran my first race on Staten Island in New York and I got hooked," he said. "Now I'm a season-ticket holder so I can compete in all the UK races this year.

"I was really bored with running and my first Spartan race changed my whole lifestyle. Being a chef meant I'd eat just about anything but racing improved my diet and I felt more energetic."

The first Spartan Race in Britain was held in 2010 at the Bassingbourn Barracks army training facility in Cambridgeshire.

Back then 1,000 people took part but this year 40,000 are estimated to race in the seven events.

Uckfield in East Sussex is the first race of 2013, held in August. The five kilometre course includes 15 obstacles.

But that's a warm-up to November's Spartan Beast at Pippingford Park, which is 25k and 25 obstacles.

As well as tasks such as scaling 25-foot high cargo nets and carrying sand bags up steep heels, there are also teams of Gladiators armed with pugil sticks hindering your progress.

But Markus, who works at the Soho House dining club, serving up dishes for the capital's celebs, said he wasn't fazed by the challenges.

He said: "Taking part in a Spartan Race is all about the rush. You're competing against others, pushing yourself. The high you get is amazing."

For more details on the races go to spartanrace.com